It’s been a wild month, no? We moved pretty high on the “Fear and Greed” index of investor sentiment during November, which was one of the dozen or so best months for the stock market in the past several decades, so we’re firmly back in “Greed” zone now, an even more abrupt turnaround in sentiment than we saw back in March, when NVIDIA put a match to the A.I. enthusiasm rocket. As always, the time when it feels worst to invest is the best time for buying, at least in the short term (if you’re going to hold for ten or twenty years, then the price you pay still matters… but it matters a lot less).

We’ve talked about that before, the chart of the “Fear and Greed” index is clearly tracks the moves in the S&P 500 chart in any given year — the stock market itself, during any relatively brief period of time like a few months, is largely a measure of the emotional wellbeing of investors around the world. I dug into the idea of this “sentiment” as a buying indicator in more detail in early October, for example, when we were drifting down to “extreme fear” and interest rates shifts were freaking people out, and that turned out to be a good “dip” to buy in the broad market… at least for the moment.

And that was further reinforced, down at the daily level, by an interesting report from Bespoke that Liz Ann Sonders tweeted out this week… buy only on days after a down day in the market? You get 785% gains… buy only after an up day? Only 17% gains. As she says, not exactly replicable, not a strategy, but still fascinating… buying when things are at least slightly gloomy is clearly better than buying when you’ve been cheered by an “up” day, and the tendency is clearly for a bad day to be followed by an up day but the reverse is not true — all things tend to revert to the mean, but in this case, with the market over the past 30 years, the mean has clearly been “up”.

Maybe that should be obvious, buying at a price that just fell is a lot better, in the short term, than buying at a price that just rose… but it’s clearly not obvious enough to make people ...